An integrative mathematical model for timing treatment toxicity and Zeitgeber impact in colorectal cancer cells.

Increasing evidence points to a role of the circadian clock in the regulation of cancer hallmarks with a strong impact on the understanding and treatment of this disease. Anti-cancer treatment can be personalized considering treatment timing. Here we present a new mathematical model based on data from three colorectal cancer cell lines and core-clock knock-outs, which couples the circadian and drug metabolism network, and that allows to determine toxicity profiles for a given drug and cell type. Moreover, this model integrates external Zeitgebers and thus may be used to fine-tune toxicity by using external factors, such as light, and therefore, to a certain extent, help fitting the endogenous rhythms of the patients to a defined clinic routine facilitating the implementation of time-dependent treatment in clinical practice.

Individual costs and community benefits: Collectivism and individuals' compliance with public health interventions.

Differences in national responses to COVID-19 have been associated with the cultural value of collectivism. The present research builds on these findings by examining the relationship between collectivism at the individual level and adherence to public health recommendations to combat COVID-19 during the pre-vaccination stage of the pandemic, and examines different characteristics of collectivism (i.e., concern for community, trust in institutions, perceived social norms) as potential psychological mechanisms that could explain greater compliance. A study with a cross-section of American participants (N = 530) examined the relationship between collectivism and opting-in to digital contact tracing (DCT) and wearing face coverings in the general population. More collectivistic individuals were more likely to comply with public health interventions than less collectivistic individuals. While collectivism was positively associated with the three potential psychological mechanisms, only perceived social norms about the proportion of people performing the public health interventions explained the relationship between collectivism and compliance with both public health interventions. This research identifies specific pathways by which collectivism can lead to compliance with community-benefiting public health behaviors to combat contagious diseases and highlights the role of cultural orientation in shaping individuals' decisions that involve a tension between individual cost and community benefit.

Avoiding N-nitrosodimethylamine formation in metformin pharmaceuticals by limiting dimethylamine and nitrite.

Since late 2019, concerns regarding trace levels of the probable human carcinogen N-dimethylnitrosamine (NDMA) in Metformin-containing pharmaceuticals have been an issue if they exceeded the maximum allowable intake of 96 ng/day for a medicine with long-term intake. Here, we report results from an extensive analysis of NDMA content along the active pharmaceutical ingredient (API) manufacturing process as well as two different drug product manufacturing processes. Our findings confirm that Metformin API is not a significant source of NDMA found in Metformin pharmaceuticals and that NDMA is created at those steps of the drug product manufacturing that introduce heat and nitrite. We demonstrate that reduction of nitrite from excipients is an effective means to reduce NDMA in the drug product. Limiting residual dimethylamine in the API has proven to be another important factor for NDMA control as dimethylamine leads to formation of NDMA in the drug products. Furthermore, analysis of historical batches of drug products has shown that NDMA may increase during storage, but the levels reached were not shelf-life limiting for the products under study.

Programmed Cell Death Ligand-1 (PDL-1) Correlates With Tumor Infiltration by Immune Cells and Represents a Promising Target for Immunotherapy in Endometrial Cancer.

BACKGROUND/AIM: Endometrial carcinoma (EC) is one of the most common gynecological cancers in the Western Hemisphere. Nevertheless, there are not enough appropriate treatment options, especially for advanced stages. The immune checkpoint blockade represents a promising alternative to established cancer therapies by suppressing the immune-inhibitory activity of the immune checkpoint factors programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1). In the present study, we characterized the clinical relevance of the biomarker PD-L1 expression in terms of its prognostic capabilities in EC. PATIENTS AND METHODS: Tumor tissue samples from 87 EC patients were retrospectively analyzed by immunohistochemistry (PD-L1, p16, estrogen receptor, progesterone receptor, HER2/neu, Ki-67, CD3, CD20, CD68). RESULTS: A total of 17.3% of EC patients were PD-L1 positive. PD-L1 status did not represent a suitable prognostic marker in EC, but correlated with T3/T4stage, positive lymph node status, p16 expression, and absence of estrogen and progesterone receptor. PD-L1 positive tissues showed increased infiltration with lymphocytes, monocytes, and macrophages, although not statistically significant in every case. CONCLUSION: In EC, PD-L1 expression has no prognostic significance, but correlates with other oncogenic factors and indicates increased infiltration of the tumor with immune cells. Thus, PD-1/PD-L1 immunecheckpoint blockade seems to be very promising, at least in a subset of EC patients.

Facilitating the Decision-Making Process After a Nuclear Accident: Case Studies in the Netherlands and Slovakia.

Nuclear accidents do not occur frequently, but their biological, psychosocial, and/or economic consequences may be severe. Hence, a thorough preparation for nuclear emergencies is needed to provide appropriate actions. During the transition phase of an accident, it is vital to include stakeholders in the decision-making process in order to gain support for the recovery strategy to be implemented as well as to share different perspectives, knowledge, and views on the decision problem. Because nuclear accidents are complex, involving many relevant factors that range from technical aspects such as health effects and costs to nontechnical issues such as social acceptance, a multicriteria decision analysis (MCDA) may facilitate the decision-making process. The aim of this study was to investigate the usefulness of MCDA in the transition phase of a nuclear accident. To this end, an MCDA tool, which uses the weighted sum of a set of normalized criteria, was explored in exercises carried out in panel meetings with a selected set of (largely) governmental stakeholders. The panel meetings were performed in the Netherlands and the Slovak Republic. The exercises were based on a fictitious case study that affected the urban environment of a small city. Prior to the meetings, a set of 8 possible recovery strategies was identified. The use of the MCDA tool showed that it facilitated the decision-making process because it allowed for a structured and transparent approach in which stakeholders with diverse backgrounds can express their opinions and perspectives and reach consensus on the most appropriate recovery strategy. As such, it could be applied to a broader field of research involving any chemical release that necessitates an extended recovery strategy. Future research is needed in order to incorporate psychosocial effects of a nuclear accident as well as a broader group of stakeholders in exercises. Integr Environ Assess Manag 2021;17:376-387. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Double jeopardy - Double remedy? The effectiveness of self-affirmation for improving doubly disadvantaged students' mathematical performance.

This study examines the effectiveness of a self-affirmation intervention to improve academic achievement for students with a "double-jeopardy status" of belonging to two potentially disadvantaged groups at the same time: girls with a minority background. The method established in the U.S. is adapted to the German cultural context and evaluated for its immediate and medium-term efficacy on math achievement among girls as well as among ethnic minority youth after the transition to secondary school. We applied a double-blind pre-post experimental design with randomized treatment allocation in 11 schools (N = 820, seventh graders with various ethnic backgrounds). Following the intervention of a brief in-class writing assignment about their personal values, students performed a standardized mathematics test. A follow-up achievement test, but no intervention, was administered eight weeks later to assess the midterm effectiveness of the treatment. Between assessments students received a written feedback about their scores in the math test. The multi-level linear model results show that (1) double-jeopardy in math performance exists, as shown by independent negative effects of female gender and Turkish or Arab minority group membership; (2) Girls from all ethnic backgrounds and students with Turkish immigrant background in the intervention group performed significantly better in the mathematics test immediately after the intervention than their peers in the control group. (3) Eight weeks later, the intervention effect only persisted for students with minority ethnic backgrounds: Turkish and Arabic students in the intervention group scored significantly higher in the standardized mathematics test compared to their peers in the control group. (4) We found no support for a triple interaction effect of treatment, ethnic background, and gender. That is, girls with a Turkish or an Arabic background did not benefit more from the self-affirmation intervention than other minority or female students. Results are discussed in relation to self-affirmation theory and how such interventions can be applied in secondary school mathematics curricula.

Karyopherin Alpha 2 Is an Adverse Prognostic Factor in Clear-Cell and Papillary Renal-Cell Carcinoma.

BACKGROUND: Karyopherin α2 (KPNA2) is involved in the nucleocytoplasmic transport system and is functionally involved in the pathogenesis of various solid tumors by the translocation of cancer associated cargo proteins. However, the role of KPNA2 in renal-cell carcinoma (RCC) is still unknown. The aim of the present study was to investigate the protein expression of KPNA2 in cancerous and healthy renal tissues to evaluate its prognostic value in RCC. PATIENTS AND METHODS: We assessed KPNA2 protein expression via immunohistochemistry in a well-characterized cohort of 240 RCC patients by using a quantitative image analysis software. In addition, we analyzed publicly available gene expression data from The Cancer Genome Atlas (TCGA). RESULTS: A subgroup of clear-cell RCC (ccRCC) showed elevated protein expression levels of KPNA2. Most remarkably, we detected a correlation between high KPNA2 protein expression and shorter overall survival times as well as higher tumor stage and International Society of Urologic Pathology grade in ccRCC. However, the prognostic value of KPNA2 was not confirmed by multivariate Cox regression analysis when tested together with strong prognostic factors like tumor stage, lymph node metastasis, International Society of Urologic Pathology grade, and resection status. The results of the TCGA gene expression data analysis confirmed the prognostic value of KPNA2 in ccRCC. Additionally, KPNA2 expression was identified as an adverse factor in papillary RCC at the transcript level. CONCLUSION: KPNA2 appears to be involved in the carcinogenesis of RCC and functions as a novel prognostic indicator.

The knockdown of the Mediator complex subunit MED15 restrains urothelial bladder cancer cells' malignancy.

The Mediator complex, a multi-subunit protein complex, plays an integral role in regulating transcription. Genetic alterations of the mediator subunit 15 (MED15) in separate tumor entities have been described previously. However, till now, not much is known about the role of MED15 in urothelial bladder cancer (BCa). Using cBioPortal, database analysis was executed for the mRNA expression and survival analysis of MED15 in BCa. Immunohistochemistry (IHC) analysis against MED15 was performed on tissue microarrays with 18 benign, 126 BCa, and 38 metastases samples. The intensity evaluation was performed using a staining intensity score from 0 to 3 and associated with clinicopathological data. The BCa cell lines T24 and TCCSUP were used for the functional investigation. After the MED15 knockdown by small interfering (si)RNA, cell proliferation, migration and invasion were investigated. On the mRNA level, only a low number of alterations (2%) was found for MED15 in BCa. Due to the small count of events, there were no significant differences or tendencies in survival. For IHC, MED15 was found to have a higher expression in non-muscle invasive BCa compared with benign and muscle invasive BCa. For survival analysis, no significant differences between samples with or without overexpression of MED15 were found. In the functional analysis, proliferation, migration, and invasion were significantly reduced in BCa-cells following the transient siRNA-mediated MED15 knockdown. In summary, MED15 appears to play a role in the tumor parameters proliferation, migration, and invasion in BCa, but further investigations are necessary.

The knockdown of the mediator complex subunit MED30 suppresses the proliferation and migration of renal cell carcinoma cells.

BACKGROUND: The mediator complex consists of 33 subunits and plays a central role in transcription. Studies have already described the involvement of individual subunits, especially in carcinogenesis. With regard to the subunit MED30, this has, so far, only been confirmed in gastric and breast carcinoma. The role of MED30 in urological tumours is unknown. MATERIALS AND METHODS: First, a database analysis using cBioPortal was performed for the mRNA expression and survival analysis of MED30 in clear cell renal cell carcinoma (ccRCC) and papillary RCC (pRCC). The immunohistochemical analysis (IHC) against MED30 was performed on tissue microarrays (TMA), with benign, ccRCC, pRCC samples, and ccRCC-metastases. Intensity evaluation was performed using the IRS (Immunoreactive Score). The ccRCC cell lines ACHN and A-498 were used for the functional investigation of proliferation, migration, and invasion after the knockdown of MED30 by siRNA. RESULTS: In a database analysis by cBioPortal, it was shown that mRNA overexpression of MED30 in the pRCC was significantly associated with a poorer overall survival and progression-free survival. In the IHC, pRCC showed the highest level of MED30 expression, unfortunately without significant results in the survival analysis. The knockdown of MED30 resulted in a significant decrease in proliferation, migration, and invasion in ccRCC. CONCLUSION: In summary, MED30 seems to be involved in the progression of the RCC.

The Mediator complex subunit MED15, a promoter of tumour progression and metastatic spread in renal cell carcinoma.

BACKGROUND/OBJECTIVE: MED15 is a part of the multiprotein Mediator complex which is involved in the transcription of polymerase (Pol) II-dependent genes. Several studies in this field have reported altered expressions of distinct subunits in human malignancy. However, the role of MED15 in renal cell carcinoma (RCC) has not be investigated yet. METHODS: First, we performed an RNA expression and survival analysis of MED15 in RCC by using the database cBioPortal. To confirm these data on the protein level, we executed immunohistochemical (IHC) staining against MED15 on a tissue microarray containing 184 samples of the most common subtypes of the tumour at the various stages. Further, we performed functional analysis including proliferation, migration, and invasion assays on the RCC cell lines A-498 and ACHN following the siRNA-mediated MED15 knockdown. RESULTS: On the mRNA level, higher expression of MED15 was associated with worse patient survival rates. IHC staining validated this tendency, unfortunately the results were not significant. However, supporting this tendency, in vitro-assays showed a significant decrease in proliferation, migration, and invasion after knockdown of MED15. CONCLUSION: The research concludes that MED15 does seem to play a tumour promoting role in the progression and metastatic spread of renal cell carcinoma.

PD-L1 (CD274) and PD-L2 (PDCD1LG2) promoter methylation is associated with HPV infection and transcriptional repression in head and neck squamous cell carcinomas.

BACKGROUND: DNA methylation of the immune checkpoint gene PD-L1 has recently been shown to be associated with PD-L1 mRNA expression in various malignancies. This study aimed to investigate the association of PD-L1 and PD-L2 methylation with mRNA expression, immune cell infitration, protein expression and human papilloma virus (HPV) infection in head and neck squamous cell carcinoma (HNSCC) patients. RESULTS: DNA methylation of PD-L1 and PD-L2 correlates inversely with mRNA expression (PD-L1: p ≤ 0.002; PD-L2: p ≤ 0.014). Methylation of specific CpG-sites of both PD-L1 and PD-L2 were further significantly associated with HPV infection in the TCGA cohort. Immune cell infiltrates correlated significantly with PD-L1 and PD-L2 methylation. In the validation cohort, PD-L1 protein expression was associated with PD-L1 hypomethylation (p = 0.012). CONCLUSIONS: DNA methylation of PD-L1 and PD-L2 is associated with transcriptional silencing and HPV infection in HNSCCs. Additional studies are warranted to test PD-L1 and PD-L2 methylation as predictive biomarkers for response to immunotherapies (e.g. pembrolizumab and nivolumab) that target the PD-L1/PD-L2/PD-1 immune checkpoint axis. MATERIALS AND METHODS: PD-L1 and PD-L2 promoter methylation and its mRNA expression were analyzed based on Infinium HumanMethylation450 BeadChip and RNA-Seq (both Illumina, Inc.) data in a representative HNSCC patient cohort (n = 528) enrolled by The Cancer Genome Atlas (TCGA) Research Network. A validation cohort consisting of 168 HNSCC patients treated at the University Hospital Bonn was analyzed regarding PD-L1 and PD-L2 promoter methylation by means of methylation-specific quantitative real-time PCR. PD-L1 protein expression in the validation cohort was quantified via immunohistochemistry (PD-L1 antibody clone 22C3, Dako/Agilent Technologies, Inc.).

The Contrasting Role of the Mediator Subunit MED30 in the Progression of Bladder Cancer.

BACKGROUND/AIM: The Mediator complex is a key regulator of gene transcription, and several studies have demonstrated altered expression of particular subunits in diverse human diseases, especially cancer. To date, nothing is known about the role of MED30 in bladder cancer. MATERIALS AND METHODS: We, therefore, performed an RNA expression and survival analysis of the subunit MED30 in 537 samples of bladder cancer by using the database cBioPortal. To validate these data on the protein level, we practiced immunohistochemical staining against MED30 on a tissue microarray containing 210 samples of all tumour stages and performed survival analyses. For functional analysis, the siRNA-mediated knockdown of MED30 was performed in the cell lines T24 and TCCSUP followed by proliferation, migration, and invasion assays. RESULTS: On the mRNA and protein levels, higher expression of MED30 is associated with better patient survival. In accordance with this, advanced T- and N-stages showed lower expression of MED30. In contrast, knockdown of MED30 led to reduction of the tumour parameters proliferation, migration, and invasion in the BCa cell lines. CONCLUSION: MED30 appears to be integrated in the progression of the urothelial tumour in the bladder.

PD-L1: a novel prognostic biomarker in head and neck squamous cell carcinoma.

BACKGROUND: The PD-1 receptor and its ligands PD-L1 and PD-L2 are known to be significantly involved in T-cell regulation. Recent studies suggest that PD-L1 expression in malignant tumors contributes to an immunosuppressive microenvironment and disruption of antitumoral immune response. Drugs targeting this pathway are already tested in clinical trials against several tumor entities with promising results. However, until now comprehensive data with regard to PD-L1 and PD-L2 expression in head and neck squamous cell carcinoma (HNSCC) is still lacking. PATIENTS AND METHODS: We assessed PD-L1 and PD-L2 expression via immunohistochemistry in two independent cohorts of 293 HNSCC patients. RESULTS: A significant subset of HNSCC showed high expression levels of PD-L1. Most remarkable, we detected a strong correlation between PD-L1 expression and overall survival time in both HNSCC cohorts. Further, in multivariate cox proportional hazard models, PD-L1 dominates as the strongest prognostic factor of patient's outcome in HNSCC, leaving even tumor stage and distant metastasis behind. Moreover, strong PD-L1 expression was associated with the presence of distant metastases in a subset of cases. CONCLUSIONS: In summary, while the significance of PD-L2 in HNSCC seems to minor, we show that PD-L1 expression is common in HNSCC and, more importantly, a both robust and strong prognostic biomarker. In this respect, our results provide hints on further application of therapies targeting the PD-1/PD-L1 pathway in HNSCC. Investigation of response and outcome of patients receiving anti-PD-1/PD-L1 containing therapies in correlation with PD-L1 expression analysis should be an important task for the future. STATEMENT OF TRANSLATIONAL RELEVANCE: In spite of improved treatment options and increasing knowledge of molecular alterations in HNSCC, the survival rate has not been dramatically changed in the past decades. Pies are missing in HNSCC. One promising candidate in cancer immune therapy is PD-L1. Drugs targeting PD-L1 or its receptor PD-1 are subject of several clinical studies in different cancer entities. However, comprehensive data about PD-L1 expression in HNSCC and therefore a rational basis for anti PD-L1/PD-1 therapy in HNSCC is lacking. Here, we provide wide-ranging data about PD-L1 expression in HNSCC of all major localizations. We observed a strong correlation between expression of PD-L1 and reduced overall survival time. Furthermore, high PD-L1 expression was identified as a strong prognostic factor of patient's outcome when verified together with recognized prognostic factors.

MTSS1 is epigenetically regulated in glioma cells and inhibits glioma cell motility.

Epigenetic silencing by DNA methylation in brain tumors has been reported for many genes, however, their function on pathogenesis needs to be evaluated. We investigated the MTSS1 gene, identified as hypermethylated by differential methylation hybridization (DMH). Fifty-nine glioma tissue samples and seven glioma cell lines were examined for hypermethylation of the MTSS1 promotor, MTSS1 expression levels and gene dosage. GBM cell lines were treated with demethylating agents and interrogated for functional consequences of MTSS1 expression after transient transfection. Hypermethylation was significantly associated with IDH1/2 mutation. Comparative SNP analysis indicates higher incidence of loss of heterozygosity of MTSS1 in anaplastic astrocytomas and secondary glioblastomas as well as hypermethylation of the remaining allele. Reversal of promoter hypermethylation results in an increased MTSS1 expression. Cell motility was significantly inhibited by MTSS1 overexpression without influencing cell growth or apoptosis. Immunofluorescence analysis of MTSS1 in human astrocytes indicates co-localization with actin filaments. MTSS1 is down-regulated by DNA methylation in glioblastoma cell lines and is part of the G-CIMP phenotype in primary glioma tissues. Our data on normal astrocytes suggest a function of MTSS1 at focal contact structures with an impact on migratory capacity but no influence on apoptosis or cellular proliferation.

Dynamics of Vector-Host Interactions in Avian Communities in Four Eastern Equine Encephalitis Virus Foci in the Northeastern U.S.

BACKGROUND: Eastern equine encephalitis (EEE) virus (Togaviridae, Alphavirus) is a highly pathogenic mosquito-borne zoonosis that is responsible for occasional outbreaks of severe disease in humans and equines, resulting in high mortality and neurological impairment in most survivors. In the past, human disease outbreaks in the northeastern U.S. have occurred intermittently with no apparent pattern; however, during the last decade we have witnessed recurring annual emergence where EEE virus activity had been historically rare, and expansion into northern New England where the virus had been previously unknown. In the northeastern U.S., EEE virus is maintained in an enzootic cycle involving the ornithophagic mosquito, Culiseta melanura, and wild passerine (perching) birds in freshwater hardwood swamps. However, the identity of key avian species that serve as principal virus reservoir and amplification hosts has not been established. The efficiency with which pathogen transmission occurs within an avian community is largely determined by the relative reservoir competence of each species and by ecological factors that influence contact rates between these avian hosts and mosquito vectors. METHODOLOGY AND PRINCIPLE FINDINGS: Contacts between vector mosquitoes and potential avian hosts may be directly quantified by analyzing the blood meal contents of field-collected specimens. We used PCR-based molecular methods and direct sequencing of the mitochondrial cytochrome b gene for profiling of blood meals in Cs. melanura, in an effort to quantify its feeding behavior on specific vertebrate hosts, and to infer epidemiologic implications in four historic EEE virus foci in the northeastern U.S. Avian point count surveys were conducted to determine spatiotemporal host community composition. Of 1,127 blood meals successfully identified to species level, >99% of blood meals were from 65 avian hosts in 27 families and 11 orders, and only seven were from mammalian hosts representing three species. We developed an empirically informed mathematical model for EEE virus transmission using Cs. melanura abundance and preferred and non-preferred avian hosts. To our knowledge this is the first mathematical model for EEE virus, a pathogen with many potential hosts, in the northeastern U.S. We measured strong feeding preferences for a number of avian species based on the proportion of mosquito blood meals identified from these bird species in relation to their observed frequencies. These included: American Robin, Tufted Titmouse, Common Grackle, Wood Thrush, Chipping Sparrow, Black-capped Chickadee, Northern Cardinal, and Warbling Vireo. We found that these bird species, most notably Wood Thrush, play a dominant role in supporting EEE virus amplification. It is also noteworthy that the competence of some of the aforementioned avian species for EEE virus has not been established. Our findings indicate that heterogeneity induced by mosquito host preference, is a key mediator of the epizootic transmission of vector-borne pathogens. CONCLUSION AND SIGNIFICANCE: Detailed knowledge of the vector-host interactions of mosquito populations in nature is essential for evaluating their vectorial capacity and for assessing the role of individual vertebrates as reservoir hosts involved in the maintenance and amplification of zoonotic agents of human diseases. Our study clarifies the host associations of Cs. melanura in four EEE virus foci in the northeastern U.S., identifies vector host preferences as the most important transmission parameter, and quantifies the contribution of preference-induced contact heterogeneity to enzootic transmission. Our study identifies Wood Thrush, American Robin and a few avian species that may serve as superspreaders of EEE virus. Our study elucidates spatiotemporal host species utilization by Cs. melanura in relation to avian host community. This research provides a basis to better understand the involvement of Cs. melanura and avian hosts in the transmission and ecology of EEE virus and the risk of human infection in virus foci.

Threshold law for attractive inverse-cube interactions.

For scattering by potentials with attractive inverse-cube (-C3/r3) tails, the threshold law for elastic collisions is presented. The expansion of the scattering phase shift contains all terms up to and including O(k2) and only relies on the value of the threshold quantum number's remainder Δ∈[0,1), which accounts for short-range deviations of the full potential from the pure -C3/r3 form. In contrast to previous approaches, the threshold law presented provides a connection to the regular solution at zero energy as well as to the position of a weakly bound s-wave state.

Nuclear exclusion of TET1 is associated with loss of 5-hydroxymethylcytosine in IDH1 wild-type gliomas.

The recent identification of isocitrate dehydrogenase 1 (IDH1) gene mutations in gliomas stimulated various studies to explore the molecular consequences and the clinical implications of such alterations. The Cancer Genome Atlas Research Network showed evidence for a CpG island methylator phenotype in glioblastomas that was associated with IDH1 mutations. These alterations were associated with the production of the oncometabolite, 2-hydroxyglutarate, that inhibits oxygenases [ie, ten-eleven translocation (TET) enzymes involved in the oxidation of 5-methylcytosine to 5-hydroxymethylcytosine (5hmC)]. We investigated 60 gliomas for 5hmC presence, 5-methylcytosine content, TET1 expression, and IDH1 mutation to gain insight into their relationships on a histological level. Of gliomas, 61% revealed no immunoreactivity for 5hmC, and no correlation was observed between IDH1 mutations and loss of 5hmC. Interestingly, expression of TET1 showed remarkable differences regarding overall protein levels and subcellular localization. We found a highly significant (P = 0.0007) correlation between IDH1 mutations and nuclear accumulation of TET1, but not with loss of 5hmC. Of 5hmC-negative gliomas, 70% showed either exclusive or dominant cytoplasmic expression, or no detectable TET1 protein (P = 0.0122). Our data suggest that the loss of 5hmC is a frequent event in gliomas, independent of IDH1 mutation, and may be influenced by the nuclear exclusion of TET1 from the nuclei of glioma cells.

Influence of higher-order dispersion coefficients on near-threshold bound and continuum states: application to 88Sr2.

We give a simple description of quantum states near the dissociation threshold of deep interatomic potentials. The influence of the potential tail is separated from effects due to the interaction at short distances. We present a general formalism which is valid for weakly bound and low-energy continuum states, both for vanishing and non-vanishing angular momentum. Its applicability is demonstrated for the example of the electronic ground state of the strontium dimer (88)Sr(2). With an appropriate choice of the potential tail that includes higher-order dispersion coefficients, all short-range effects are incorporated via the threshold quantum number ν(D) and one further parameter accounting for residual short-range effects.

A game with many players: control of gdh transcription in Corynebacterium glutamicum.

Glutamate dehydrogenase is a central enzyme connecting nitrogen and carbon metabolism via its precursors ammonium and oxoglutarate and its product glutamate. In Corynebacterium glutamicum glutamate dehydrogenase is especially important, since it is a key enzyme for the biotechnological production of the flavour enhancer L-glutamate. In this study, the regulation of gdh transcription was investigated. While originally described as a constitutively expressed gene, we could show that gdh transcription is highly variable depending on environmental conditions. Regulation of the gdh gene by the C. glutamicum nitrogen control protein AmtR was analyzed in detail in this study.

FarR, a putative regulator of amino acid metabolism in Corynebacterium glutamicum.

With the publication of the Corynebacterium glutamicum genome sequence, a global characterization of genes controlled by functionally uncharacterized transcriptional regulators became possible. We used DNA microarrays in combination with gel retardation experiments to study gene regulation by FarR, a HutC/FarR-type regulator of the GntR family. Based on our results, FarR seems to be involved in the regulation of amino acid biosynthesis in C. glutamicum. Especially, transcript levels of the arg cluster and the gdh gene are influenced by deletion of farR.